Quoted from CactusJack:
If you have 73VAC at the bottom connector of regulator board with connector plugged in, your transformer is good.
Roller Disco Update:
Okay, so finally got into the office and ran through some checks:
Rebuilt Power board
Stock CPU board
Ground lines on each board to the ground plane of the backbox are done
EMI line filter - 120VAC
A2J1 not plugged into board
p1 - 11.7
p2 - 11.7
p3 - GND
p4 - 14.2
p5 - 14.2
p6 and p7 would only show vac when I put red/black leads ac into each which showed ~73vac
Plugged A2J1 into power board and tested A2J2 and J3 (the J2 and J3 plugs were not plugged in)
p1 - 5.1
p2 - 5.1
p6 - -12.15
P1 - 60v
p3 - 42
p7 - 3.7-3.8
p8 - 8
I plugged J2 in, and tested voltage at the 2 capacitors next to the J1 plug on the cpu board
C16 had 5v. C17 had 12v, not sure why i didn't get -12, the cap shows the negative on the lower side.
I then plugged in J3 to the power board and tested voltage at the plug with the displays running
I got ~41-52v during 60v displays changing and 31-38v when the 42v display changed. I did each display individually as well and they were of course much brighter by themselves.
So looks like the power is good, ish? See any issue with the display line voltage? seems to drop a lot.
Game booted but lots of switch issues as many things didn't register, still have to troubleshoot of course but now that the power is up I can move forward.